Casein dispersions



Patented Dec. 8, 1936 PATENT OFFICE CASEIN DISPERSION S Frank G. Uhler,Newburgh, E. I. du Pont de Nemours mington, DeL, a corporation N. TL,assignor to & Company, Wilof Delaware No Drawing. Application February9, 1932, Serial No. 591,933

8 Claims.

This invention relates to casein dispersions and, more particularly, todispersions of casein in water and sulphonated fixed or fatty acid oilsand to artificial leather prepared from such dispersions.

Heretofore casein has been dispersed in water with the aid of eitheracid or basic dispersing agents, but a neutral dispersing agent for thispurpose has not been known.

Obviously, a neutral aqueous dispersion of casein has many advantages incommercial use over a, dispersion which is distinctly acid or alkaline.

An object of the present invention is the provision of a neutral aqueousdispersion of casein that will form a tough and flexible casein film. Afurther object is the preparation of artificial leather having a tough,flexible casein surface coating. Other objects of the invention will beapparent from the description of the invention given hereinafter.

The above objects are accomplished according to the present invention byemploying sulphonate ed fixed or fatty acid oils as the dispersing agentfor casein in water and using a fibrous base sheet with the caseindispersion so obtained to produce an artificial leather.

It was discovered that the sulphonated fixed or fatty acid oils, thatis, such oils as castor, coconut, corn, olive, and similar oils,hereinafter referred to as fixed oils rather than fatty acid oils, whichlatter term might be construed to exclude glycerides of oleic acid andsuch acids which are not strictly fatty acids, function to givehomogeneous neutral dispersions of casein in Water and have the furtheradvantage that, being compounds of low vapor pressure, they function aspermanent softening agents or plas-- ticizers in films produced fromsuch dispersions. sulphonated castor oil, commercially known as Turkeyred oil, is the preferred dispersing agent and the following specificexamples are given to illustrate dispersions employing thisagent-Percentages are by weight.

Example 1 Per cent Casein 20.0

sulphonated castor oil 5.0

Water 75.0

The above composition represents the minimum quantity of sulphonatedcastor oil which has been found to produce a satisfactory homogeneousdispersion of casein in water.

Example 2 Per cent Casein 20.0 sulphonated castor oil 70.0 Water 10.0 5

The above composition represents the maximum quantity of sulphonatedcastor which will produce a satisfactory homogeneous dispersion ofcasein in Water. If the sulphonated oil content exceeds this limit, anincomplete dispersion results which is not satisfactory for commercialuse.

.The following examples illustrate preferred specific proportions inorder to obtain a disper- 15 sion of low viscosity in view of the caseincontent, clarity and homogeneity:-

Films deposited from the compositions in Examples 3, 4 and 5 possessmarked adhesive prop- 35 erties and exceptionally satisfactory qualitiesin general for the production of artificial leather, and the like. v

The following examples illustrate dispersions employing othersulphonated oils: 4

Example 6 Per cent Casein 18.2 sulphonated olive oil 18.2 45 Water 54.5Diethylene glycol 9.1 Example 7 Per cent 50 Casein 19.4 sulphonatedcoconut oil 19.4 Water 58.3 Triethanolamine 2.9

The above examples are merely illustrative and 55 similar dispersionsmay be obtained by using other sulphonated fixed oils. Sulphonated cornand rapeseed oils may be mentioned as other specific fixed oilswhich areparticularly satisfactory, although the use of any sulphonated fixed oilis contemplated within the scope of the present invention.

Although the dispersions above described are of satisfactory clarity formost purposes, they may be improved somewhat in clarity by the additionof small amounts of triethanolamine, ethyl alcohol, and similarcompounds.

As will be understood by those skilled in the art, plasticizers may beadded to the dispersions in order to give films of increasedflexibility. Among the more common plasticizers may be mentioned glycol,diethylene glycol, and trlethylene glycol. Likewise, pigments and dyesmay be included in the dispersions to obtain colored Artificial leathermay be produced by coating fabric, paper, or other woven or feltedfibrous, flexible bases with these dispersions. The coating may becarried out by brushing or by the use of a doctor blade, or the film maybe cast on the base.

These dispersions are suitable for coating textile and paper bases toform leather substitutes for use as upholstery, automobile coverings,bookbinding materials, window shades, and other products for whichcoated fabrics of this nature are commonly used.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to beunderstood that the invention is not limited to the specific embodimentsthereof except as defined in the appended claims.

I claim:

1. A liquid composition which on drying forms a tough flexible film saidcomposition comprising as a vehicle a neutral homogeneous waterdispersion containing about 20% casein, 60% water,

and about 20% of a sulphonated fixed oil as the dispersing agent.

spears 2. A liquid composition which on drying forms a tough flexiblefilm comprising as a vehiclea neutral dispersion of about 20% of casein,75 to 10% of water, and 5 to 70% sulphonated' castor oil as thedispersing agent.

3. A liquid composition which on drying forms a tough flexible filmcomprising as a vehicle a neutral dispersion containing about 20% ofcasein in 65 to 40% water and 15-to 40% of sulphonated castor oil as thedispersing agent.

4. An artificial leather comprising. a flexible fibrous base sheet andsuperposed thereon a tough flexible surface film formed by coating oversaid sheet a liquid composition comprising as a vehicle a neutralhomogeneous dispersion containing about 20% of casein, about water, andabout 20% of a sulphonated fixed oil.

5. An artificial leather comprising a flexible fibrous base sheet andsuperposed thereon a tough flexible surface film formed by coating oversaid sheet a liquid composition comprising as a vehicle a neutralhomogeneous dispersion consisting of about 20% of casein, '75 to 10% ofwater, and about 5 to 70% sulphonated castor oil.

6. An artificial leather comprising a flexible fibrous base sheet andsuperposed thereon a tough flexible surface film formed by coating oversaid sheet a liquid composition comprising 'a pigment and: as a vehicletherefor a neutral homogeneous dispersion consisting of about 20% ofcasein, to 40% of water, and about 15 to 40% of sulphonated castor oil.

'I. A liquid composition which on drying forms a tough flexible filmcomprising as a vehicle a neutral dispersion of about 20% of casein, '15to 10% of a mixture of water and a glycol, and 5 to sulphonated fixedoil as the dispersing agent.

8. A liquid composition which on drying forms a tough flexible filmcomprising as a vehicle a neutral dispersion coating, about 20% ofcasein in 65 to 40% of a mixture of water and ethylene glycol, and 15 to40% of sulphonated castor oil as the dispersing agent.

FRANK G. UHLER;

